Method of continuous casting



y 1950 B. TARMANN 2,944,310

METHOD OF con'rmuous CASTING Filed Feb. 13. 1958 United States Patent O METHOD OF CONTINUOUS CASTING Bruno Tarmann, Albert-Bohlergasse 7, Kapfenberg, Styria, Austria Filed Feb. 13, 1958; Ser. No. 715,154 1 Claim. (01. 22-2001 v 2,944,310 Patented July 12, 1960 will proceedon the surface of the metal bath toward the teeming jet. Before reaching the teeming jet this current is braked by the wave crest which is formed around the teeming jet. At this point the entrained slag particles and any oxide skin which may be formed. are held on the surface of themetal bath whereas the lower particles of the current are entrained by the suction of the teeming jet and perform an additional part of the cycle.

The slag particles which are entrained by the teeming jet rise to the surface of the metal bath at the opposite end of the mold owing to their low weight and float on the surface of the oxide skin, from where they can easily be removed. e

The desired current can be given the desired direction and intensity by an inclination of the teeming jet. This will also ensure that the teeming jet does not move too close to the skin so that'the danger of a retardation of the growth of the solidified skin next to theteeming point the molten metal in one or more jets into the mold; The

jet impinges the surface of the metal bath'in the mold in most cases at right angles to said surface and adjacent to the axis of the billet. When the molten. metal is poured in several jets, the distribution of 'the'points in any of the jets does not disturb .the uniform growth of caused by the inflowing molten metal would reduce'the of impact of the jets on the surface of the metal bath is chosenso that the inflow of the hotter molten metal development of the solidified skin and would cause the skin to melt through at that point of the billet where the current reaches the skin zone.

The teeming currents agitate also the slag. particles which are entrained by the molten metal. They are carried by the jet from the surface of the metal bath into the depth thereof and are sometimes urged into the pasty part of the metal bath, Where they are occluded during the solidification of the metal. They are the cause of structural defects and sometimes of a breakas a result of the higher temperature of the inflowing. molten metal is avoided.

The; invention will be explained with. reference to an illustrative embodiment shown in the drawing. Fig. 1 I is a sectional viewof amold having a mold cavity of a Fig; 2

symmetrical elongated Y cross-sectional shape. shows a gate, according to the invention.

The jet 'of molten metal causes in the metal bath in the molten metal flows toward the teeming jet and is en'- through of the still molten core through the skin. Slag particles which settle on the skin of the billet insulate the molten metal .behind them against the cooling action of the mold wall and thus reduce the progress of the solidification at this point. The teeming jet may also urge the oxide skin forming on the surface of the metal bath against the mold wall, where it is then moved downwardly in intervals together with the billet during the lowering movement of the latter. This results in laps and laminations at the skin portions of the billet and consequently in indentations having rounded corners and uneven boundary surfaces at the periphery of the billet.

In order -to prevent the formation of such cold shuts it has already been proposed to cover .the metal bath bath whereby the desired temperature distribution and a movement of the metal bath are achieved.

If the teeming jet impinges the surface of the metal bath in a mold for continuous casting next to one point of the wall of the mold, the jet will cause a current which flows below the surface of the metal bath to the op posi-te point of the wall of the mold and rises along the skin layer which is solidifying there; then the current owing to their low weight.

trained by the same fora new cycle. This current of molten metal entrains also the infiowing'slag particles, which rise to the surfaceof the metal bath on the opposite side of the mold near the skin and float there These slag particlesare sometimes urged toward the teeming jet but are held back at the wave crest forming around the teeming jet before they reach the teeming jet itself. At this wave crest the slag particles can easily be skimmed off.

To obtain a'current flowing in a predetermined direction the molten metal is supplied to the mold-through a gate 5, the channel 6 of which is inclined with respect to the axis of the mold; The angle of inclination must be selected in accordance with the flow energy and the I width of the mold and may suitably amount to' 5'-10'..

I claim: A method for the continuous casting of metals which comprises forming a bath of molten metalin a mold,

v and pouring at least one jet of molten metal on the surface of said bath by passing molten metal through an elongated,.straight confining conduit .the axis of which is .inclined with respect to and crosses-the longitudinal axis of said mold below said surface, said conduit having anoutlet for discharging said metal which outlet is suflicientplane which is at right angles to said'surface is produced in said bath.

ReferencesCited in the file of thispatent UNITED STATES PATENTS.

1,788,185 Beck Jan. 6, 1931 2,682,691 Harter July 6, 1954 2,743,492 Easton May], 1956 2,193,410 Junghans May 28, 1957 

